Participants will take ondansetron then placebo plus an atypical antipsychotic drug

Drug: Ondansetron followed by placebo

Participants will take 16mg of ondansetron daily for the first three months followed by 3 months of placebo. An atypical antipsychotic drug (olanzapine,quetiapine, or aripiprazole) will also be taken throughout the 6 months treatment period.

Other Name: Zofran, Zuplenz

Experimental: Placebo followed by Ondansetron

Participants will take placebo then ondansetron plus an atypical antipsychotic drug

Drug: Placebo followed by Ondansetron

Participants will take placebo daily for the first three months followed by 3 months of 16mg of ondansetron daily. An atypical antipsychotic drug (olanzapine,quetiapine, or aripiprazole) will also be taken throughout the 6 months treatment period.

Other Name: Zofran, Zuplenz

Detailed Description:

Schizophrenia is a devastating brain disorder. Most people with schizophrenia have difficulty filtering out unimportant auditory information. They have an inability to appropriately inhibit, or gate, sensory information that enters the ear. Standard treatments do not address this problem. When the drug ondansetron is taken in addition to typical antipsychotic drugs, P50 auditory gating improves. However, ondansetron has not been used with some of the newer, atypical antipsychotic drugs. This study will evaluate the effect of combining ondansetron with newer, atypical antipsychotic drugs on P50 auditory gating.

Participants in this double-blind study will be randomly assigned to receive either ondansetron or placebo for 3 months. Upon completion of the first 3 months, participants will be crossed over to receive the other treatment for an additional 3 months. All participants will also take an atypical antipsychotic drug, including olanzapine, quetiapine, or aripiprazole. Auditory gating will be assessed using computerized cognitive testing and functional magnetic resonance imaging (fMRI) at baseline and Months 3 and 6. Vital signs and evoked potentials will be assessed at Weeks 1, 3, and 6. Clinical symptoms and cognitive abilities will also be evaluated to determine the effectiveness of ondansetron.

Eligibility

Ages Eligible for Study:

18 Years to 55 Years (Adult)

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Meets DSM-IV criteria for schizophrenia

Stable, chronic schizophrenia

Currently taking atypical medications

Use of effective form of contraception throughout study

Exclusion Criteria:

History of any alcohol or drug abuse within 3 months of study start date

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For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00149734